Adding tests and missing methods for Enso_File.

[radeusgd]

Pull Request Description

• Closes Review and add tests for Enso_File functionality #8808 - adds tests for various scenarios.
• Implements size using HEAD.
• Updates existing functions to changes in Cloud API.
• Adds stubs for *_time methods, parent, path.
• TODO: resolve the Enso_File.current_working_directory from an environment variable.
• TODO: recursive directory deletion? left for later

Important Notes

• Currently, the Cloud API does not offer an easy way to extract metadata for a file, in particular to get the parent folder from the file id.
  • We should be able to get the parent, and stuff like creation/modified time.
• We need a way to resolve paths to asset ids, for path to work as well as current_working_directory.
• What is the environment variable that will be used to feed the current_working_directory property?

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed, the GUI was tested when built using ./run ide build.